There are many reasons why zone difficulty is encountered with a well and when zone difficulty is experienced it is often desired to investigate the producing zone through existing casing perforations.
Existing tools for this purpose are primarily of the type which are limited to single operations. A perforation wash tool of conventional design cannot be utilized to perform the wash operations as well as to plasticize, acidize, etc., all in one trip through the casing. In addition, conventional wash tools utilized with ball subs may not be used to re-perforate. Accordingly, if multiple operations are to be performed the tubing string must be run into and pulled out of the casing numerous times to perform a series of operations at the producing zone. Therefore, a need exists for a multi-purpose wash tool which may be utilized not only for perforation washing operations but also for plasticizing, acidizing and re-perforation operations all during the same trip of the tubing string into the well.
Examples of various other tools including some of the structural and operational features of the instant invention are disclosed in U.S. Pat. Nos. 2,568,087, 2,970,649, 3,071,960 and 3,189,096.